tense

tense /adj./ Of programs, very clever and efficient. A tense
piece of code often got that way because it was highly bummed,
but sometimes it was just based on a great idea. A comment in a
clever routine by Mike Kazar, once a grad-student hacker at CMU:
"This routine is so tense it will bring tears to your eyes." A
tense programmer is one who produces tense code.